1. Field of the Invention
The present invention relates to a keyboard device that performs an information input operation using a touch panel, and a controller for an electronic equipment using the same, the electronic equipment controller being exemplified as a remote controller for a television (hereinafter referred to as the TV remote controller), a desk calculator, etc.
2. Description of the Related Art
A touch panel is a device that is generally arranged on the display screen of an LCD (Liquid Crystal Display), a CRT display, etc. While looking through characters, numerals or some other symbols (Pictographs usually called as icons such as graphics or images are included. A plurality of symbols may constitute a single symbol) from the front surface side of the touch panel, users touch the characters, numerals or some other symbols (hereinafter referred to as the characters) with their fingers, etc. so as to generate and output information corresponding to a position where the users have touched. This type of the touch panel has been well known in the field of ATM (Automated Teller Machine) of a bank, car navigators, etc. Further, the touch panel has also become well used in the field of compact electronic equipments such as portable information terminals, electronic dictionaries, etc.
Here, considering input devices that perform information input operation using the above-described touch panel, it would be structurally necessary that a display device such as an LCD, etc. needs to be arranged at the lower surface side of the input devices, therefore increasing the total cost of the input devices. On the other hand, since the display device is used also as the input devices, it would have an advantage of reducing an occupied space relative to the whole input devices in which to perform display and input of information. Further, it would also make possible to function the input devices as a multiple display device where the symbols displayed on a screen can be sequentially altered as needed. See Japanese Patent Application Laid-open No. H10-27053 (hereinafter referred to as the Japanese Document 1) and Japanese Patent Application Laid-open No. 2007-164767 (hereinafter referred to as the Japanese Document 2). Still further, input devices where an information input operation is performed with application of a touch panel but without application of a display device such as an LCD have been developed. See Japanese Patent Application Laid-open No. 2006-65611 (hereinafter referred to as the Japanese Document 3) and Japanese Patent Application Laid-open No. 2009-212031 (hereinafter referred to as the Japanese Document 4).
However, in the above-described conventional arts, if functions of the multiple display device are not required, it would become not necessary to especially provide the display devices of the LCD, the CRT, and the like. Accordingly, the input devices disclosed in the Patent Document 1 and the Patent Document 2 may go beyond necessary specifications, resulting in a high cost as simple input devices.
Considering the input devices disclosed in the Patent Document 3 and the Patent Document 4 where information input operations are performed with the touch panel but without the display device, it would be possible to reduce costs since no display device is applied. However, as to the input device disclosed in the Patent Document 3, from its upper surface side to its lower surface side, a display sheet (an operational display portion or a symbol printing film), a surface emission layer (or a touch panel) and a touch panel (or a surface emission layer) are laminated in this order. Further, as to the input device disclosed in the Patent Document 4, from its upper surface side to its lower surface side, a base-material film (or a symbol printing film), a touch panel and a surface emission layer are laminated in this order. Based on the structure disclosed in the Patent Document 3 and the Patent Document 4, the following problems have been arisen. That is, considering arrangement of the above laminated structure, in the arrangement where the surface emission layer is placed underneath the touch panel, a signal wiring group of the touch panel becomes easily visible from the top of the input operational surface so as not only to deteriorate visibility of the symbols but also to degrade operationability or an outer appearance of the input devices. Further, operationability of the touch panel has been lowered, so that users need relatively strong touches to the touch panel to be detected.
Moreover, as to the input devices disclosed in the Patent Document 4, the uppermost surface (or the input operational surface) of finished products (the completed input devices) has a convexoconcave surface, making the uppermost surface difficult for cleaning. Especially, at cornered portions on the convexoconcave surface, cleaning has not been satisfactorily performed, resulting in easy adhesion of dust, oil and fat contents, and the like. This causes not only deterioration of the outer appearance of the input devices but also difficulty to keep sanitary conditions in a satisfied manner. Accordingly, the input devices of the above type have not been able to use in medical care fields, clean rooms, etc.